:root {
  color-scheme: dark;
  --bg: #090a0c;
  --bg-soft: #101216;
  --surface: #15181d;
  --surface-2: #1d2228;
  --text: #f3efe7;
  --muted: #b6aea3;
  --dim: #7b746b;
  --faint: #48443f;
  --line: rgba(243, 239, 231, 0.12);
  --line-strong: rgba(243, 239, 231, 0.22);
  --amber: #f6a04d;
  --cyan: #62d6ef;
  --green: #81d39a;
  --rose: #f1788f;
  --max: 1180px;
  --radius: 8px;
  --sans: Inter, ui-sans-serif, system-ui, -apple-system, BlinkMacSystemFont, "Segoe UI", sans-serif;
  --serif: Georgia, "Times New Roman", serif;
  --mono: "SFMono-Regular", "Cascadia Code", "Roboto Mono", Consolas, monospace;
}

* {
  box-sizing: border-box;
}

html {
  scroll-behavior: smooth;
}

body {
  margin: 0;
  min-height: 100vh;
  color: var(--text);
  background:
    linear-gradient(180deg, rgba(98, 214, 239, 0.05), transparent 26rem),
    linear-gradient(120deg, rgba(246, 160, 77, 0.045), transparent 34rem),
    var(--bg);
  font-family: var(--sans);
  font-size: 16px;
  line-height: 1.6;
  -webkit-font-smoothing: antialiased;
  overflow-x: hidden;
}

body::before {
  content: "";
  position: fixed;
  inset: 0;
  pointer-events: none;
  background-image:
    linear-gradient(rgba(243, 239, 231, 0.035) 1px, transparent 1px),
    linear-gradient(90deg, rgba(243, 239, 231, 0.035) 1px, transparent 1px);
  background-size: 48px 48px;
  mask-image: linear-gradient(to bottom, black, transparent 82%);
  -webkit-mask-image: linear-gradient(to bottom, black, transparent 82%);
  z-index: -2;
}

body::after {
  content: "";
  position: fixed;
  inset: 0;
  pointer-events: none;
  opacity: 0.04;
  background-image: url("data:image/svg+xml,%3Csvg xmlns='http://www.w3.org/2000/svg' width='160' height='160'%3E%3Cfilter id='n'%3E%3CfeTurbulence type='fractalNoise' baseFrequency='.8' numOctaves='3' stitchTiles='stitch'/%3E%3C/filter%3E%3Crect width='100%25' height='100%25' filter='url(%23n)'/%3E%3C/svg%3E");
  z-index: -1;
}

a {
  color: inherit;
}

.site-shell {
  min-height: 100vh;
}

.site-header {
  position: sticky;
  top: 0;
  z-index: 20;
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 24px;
  padding: 18px clamp(18px, 4vw, 44px);
  border-bottom: 1px solid var(--line);
  background: rgba(9, 10, 12, 0.82);
  backdrop-filter: blur(16px);
}

.brand {
  display: inline-flex;
  align-items: center;
  gap: 12px;
  text-decoration: none;
  min-width: 0;
}

.brand-mark {
  display: grid;
  place-items: center;
  width: 36px;
  height: 36px;
  border: 1px solid var(--line-strong);
  border-radius: var(--radius);
  color: var(--amber);
  font-family: var(--mono);
  font-size: 12px;
  letter-spacing: 0.08em;
  background: rgba(246, 160, 77, 0.08);
}

.brand-text {
  display: grid;
  gap: 1px;
}

.brand-name {
  font-weight: 700;
  letter-spacing: 0.01em;
}

.brand-role {
  color: var(--dim);
  font-family: var(--mono);
  font-size: 11px;
  letter-spacing: 0.08em;
  text-transform: uppercase;
}

.site-nav {
  display: flex;
  align-items: center;
  gap: 6px;
  color: var(--muted);
  font-family: var(--mono);
  font-size: 12px;
  letter-spacing: 0.04em;
}

.site-nav a {
  padding: 9px 11px;
  border-radius: 6px;
  text-decoration: none;
  transition: color 180ms ease, background 180ms ease;
}

.site-nav a:hover,
.site-nav a[aria-current="page"] {
  color: var(--text);
  background: rgba(243, 239, 231, 0.06);
}

.status-pill {
  display: inline-flex;
  align-items: center;
  gap: 8px;
  color: var(--green);
}

.status-pill::before {
  content: "";
  width: 7px;
  height: 7px;
  border-radius: 50%;
  background: currentColor;
  box-shadow: 0 0 16px rgba(129, 211, 154, 0.45);
}

.hero {
  position: relative;
  display: grid;
  align-items: center;
  padding: clamp(72px, 12vw, 140px) clamp(20px, 5vw, 64px) clamp(56px, 8vw, 96px);
  overflow: hidden;
}

.hero-scene {
  position: absolute;
  inset: 0;
  opacity: 0.72;
  pointer-events: none;
}

.hero-scene svg {
  width: 100%;
  height: 100%;
}

.hero-scene .trace {
  fill: none;
  stroke: rgba(98, 214, 239, 0.28);
  stroke-width: 1;
  stroke-dasharray: 4 10;
}

.hero-scene .trace.alt {
  stroke: rgba(246, 160, 77, 0.24);
}

.hero-scene .node {
  fill: rgba(21, 24, 29, 0.88);
  stroke: rgba(243, 239, 231, 0.22);
}

.hero-scene .node.hot {
  stroke: rgba(98, 214, 239, 0.65);
}

.hero-inner {
  position: relative;
  width: min(100%, 860px);
  margin: 0 auto;
}

.eyebrow {
  display: inline-flex;
  align-items: center;
  gap: 12px;
  margin-bottom: 20px;
  color: var(--cyan);
  font-family: var(--mono);
  font-size: 12px;
  letter-spacing: 0.16em;
  text-transform: uppercase;
}

.eyebrow::before {
  content: "";
  width: 34px;
  height: 1px;
  background: currentColor;
}

.hero h1 {
  margin: 0;
  max-width: 780px;
  font-family: var(--serif);
  font-size: clamp(42px, 6.6vw, 86px);
  line-height: 0.97;
  letter-spacing: -0.025em;
  font-weight: 500;
}

.hero-lede {
  max-width: 640px;
  margin: 24px 0 0;
  color: var(--muted);
  font-size: clamp(17px, 1.8vw, 22px);
  line-height: 1.5;
}

.hero-lede strong {
  color: var(--text);
  font-weight: 650;
}

.hero-actions {
  display: flex;
  flex-wrap: wrap;
  gap: 12px;
  margin-top: 30px;
}

.button {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  gap: 10px;
  min-height: 44px;
  padding: 0 18px;
  border: 1px solid var(--line-strong);
  border-radius: 7px;
  color: var(--text);
  background: rgba(243, 239, 231, 0.045);
  text-decoration: none;
  font-family: var(--mono);
  font-size: 12px;
  letter-spacing: 0.06em;
  text-transform: uppercase;
  transition: transform 180ms ease, border-color 180ms ease, background 180ms ease;
}

.button:hover {
  transform: translateY(-1px);
  border-color: rgba(98, 214, 239, 0.7);
  background: rgba(98, 214, 239, 0.08);
}

.button.primary {
  border-color: rgba(246, 160, 77, 0.7);
  background: rgba(246, 160, 77, 0.13);
}

/* Operator stack — vertical card section */
.opstack {
  padding: clamp(56px, 8vw, 96px) clamp(20px, 5vw, 64px);
  border-top: 1px solid var(--line);
}

.opstack-inner {
  width: min(100%, var(--max));
  margin: 0 auto;
}

.opstack-head {
  display: flex;
  justify-content: space-between;
  align-items: baseline;
  gap: 18px;
  padding-bottom: 18px;
  border-bottom: 1px solid var(--line);
  margin-bottom: 26px;
}

.opstack-kicker {
  color: var(--amber);
  font-family: var(--mono);
  font-size: 12px;
  letter-spacing: 0.16em;
  text-transform: uppercase;
}

.opstack-title {
  margin: 8px 0 0;
  font-family: var(--serif);
  font-size: clamp(28px, 3.6vw, 44px);
  line-height: 1.06;
  letter-spacing: -0.018em;
  font-weight: 500;
}

.opstack-status {
  display: inline-flex;
  align-items: center;
  gap: 10px;
  color: var(--dim);
  font-family: var(--mono);
  font-size: 11px;
  letter-spacing: 0.14em;
  text-transform: uppercase;
}

.opstack-status::before {
  content: "";
  width: 7px;
  height: 7px;
  border-radius: 50%;
  background: var(--green);
  box-shadow: 0 0 14px var(--green);
}

.opstack-list {
  display: grid;
  grid-template-columns: 1fr;
  gap: 16px;
}

.opstack-card {
  position: relative;
  display: grid;
  grid-template-columns: minmax(280px, 0.42fr) minmax(0, 1fr);
  gap: clamp(24px, 4vw, 56px);
  padding: 28px 30px;
  border: 1px solid var(--line);
  border-radius: 12px;
  background: rgba(15, 17, 21, 0.74);
  backdrop-filter: blur(14px);
  transition: transform 220ms ease, border-color 220ms ease;
  overflow: hidden;
}

.opstack-card::before {
  content: "";
  position: absolute;
  left: 0;
  top: 0;
  width: 3px;
  height: 100%;
  opacity: 0.7;
}

.opstack-card.command::before {
  background: linear-gradient(180deg, var(--cyan), transparent);
}

.opstack-card.execution::before {
  background: linear-gradient(180deg, var(--amber), transparent);
}

.opstack-card.review::before {
  background: linear-gradient(180deg, var(--green), transparent);
}

.opstack-card:hover {
  transform: translateY(-2px);
}

.opstack-card.command:hover {
  border-color: rgba(98, 214, 239, 0.5);
}

.opstack-card.execution:hover {
  border-color: rgba(246, 160, 77, 0.5);
}

.opstack-card.review:hover {
  border-color: rgba(129, 211, 154, 0.5);
}

.opstack-id {
  display: flex;
  flex-direction: column;
}

.opstack-tier {
  color: var(--amber);
  font-family: var(--mono);
  font-size: 10.5px;
  letter-spacing: 0.16em;
  text-transform: uppercase;
  margin-bottom: 8px;
}

.opstack-card.command .opstack-tier {
  color: var(--cyan);
}

.opstack-card.execution .opstack-tier {
  color: var(--amber);
}

.opstack-card.review .opstack-tier {
  color: var(--green);
}

.opstack-name {
  margin: 0 0 6px;
  font-family: var(--serif);
  font-size: clamp(30px, 3.4vw, 42px);
  line-height: 1.05;
  letter-spacing: -0.02em;
  font-weight: 500;
}

.opstack-name .alt {
  color: var(--dim);
  font-family: var(--mono);
  font-size: 13px;
  letter-spacing: 0.1em;
  text-transform: uppercase;
  margin-left: 6px;
  vertical-align: middle;
}

.opstack-role {
  color: var(--text);
  font-weight: 650;
  font-size: 13px;
  letter-spacing: 0.02em;
  margin-top: 8px;
}

.opstack-desc {
  margin: 10px 0 0;
  color: var(--muted);
  font-size: 14.5px;
  line-height: 1.55;
}

.opstack-bullets {
  align-self: center;
  padding-left: clamp(0px, 2vw, 24px);
  border-left: 1px solid rgba(243, 239, 231, 0.075);
}

.opstack-bullets-label {
  display: block;
  color: var(--dim);
  font-family: var(--mono);
  font-size: 10px;
  letter-spacing: 0.14em;
  text-transform: uppercase;
  margin-bottom: 12px;
}

.opstack-bullets ul {
  list-style: none;
  padding: 0;
  margin: 0;
  display: grid;
  gap: 10px;
}

.opstack-bullets li {
  color: var(--muted);
  font-size: 14.5px;
  line-height: 1.5;
  padding-left: 18px;
  position: relative;
}

.opstack-bullets li::before {
  content: "\203A";
  position: absolute;
  left: 0;
  top: -1px;
  color: var(--cyan);
  font-family: var(--mono);
  font-size: 15px;
}

.opstack-card.execution .opstack-bullets li::before {
  color: var(--amber);
}

.opstack-card.review .opstack-bullets li::before {
  color: var(--green);
}

.opstack-gate {
  display: flex;
  justify-content: space-between;
  align-items: center;
  gap: 18px;
  margin-top: 22px;
  padding: 18px 22px;
  border: 1px solid rgba(129, 211, 154, 0.3);
  border-radius: 12px;
  background: rgba(129, 211, 154, 0.06);
}

.opstack-gate-key {
  display: inline-flex;
  align-items: center;
  gap: 12px;
  color: var(--green);
  font-family: var(--mono);
  font-size: 12px;
  letter-spacing: 0.14em;
  text-transform: uppercase;
}

.opstack-gate-key::before {
  content: "";
  width: 9px;
  height: 9px;
  border-radius: 50%;
  background: currentColor;
  box-shadow: 0 0 18px currentColor;
}

.opstack-gate-copy {
  color: var(--muted);
  font-size: 14px;
  text-align: right;
  max-width: 460px;
}

.opstack-gate-copy strong {
  color: var(--text);
}

.section {
  padding: clamp(62px, 9vw, 110px) clamp(20px, 5vw, 64px);
  border-top: 1px solid var(--line);
}

.section.alt {
  background: rgba(243, 239, 231, 0.025);
}

.section-inner {
  width: min(100%, var(--max));
  margin: 0 auto;
}

.section-kicker {
  color: var(--amber);
  font-family: var(--mono);
  font-size: 12px;
  letter-spacing: 0.16em;
  text-transform: uppercase;
}

.section h2 {
  max-width: 780px;
  margin: 12px 0 0;
  font-family: var(--serif);
  font-size: clamp(28px, 4vw, 52px);
  line-height: 1.04;
  letter-spacing: -0.018em;
  font-weight: 500;
}

.section-intro {
  max-width: 760px;
  margin: 18px 0 0;
  color: var(--muted);
  font-size: 17px;
}

.lane-grid {
  display: grid;
  grid-template-columns: repeat(3, minmax(0, 1fr));
  gap: 14px;
  margin-top: 38px;
}

.lane-card,
.guide-card,
.note-card {
  border: 1px solid var(--line);
  border-radius: var(--radius);
  background: rgba(15, 17, 21, 0.72);
}

.lane-card {
  padding: 22px;
}

.lane-card h3,
.guide-card h3,
.note-card h3 {
  margin: 0;
  font-size: 16px;
  letter-spacing: 0.01em;
}

.lane-card p,
.guide-card p,
.note-card p {
  margin: 12px 0 0;
  color: var(--muted);
}

.lane-tag {
  display: inline-flex;
  margin-bottom: 18px;
  color: var(--cyan);
  font-family: var(--mono);
  font-size: 11px;
  letter-spacing: 0.08em;
  text-transform: uppercase;
}

.breakpoints {
  position: relative;
  overflow: hidden;
  background:
    linear-gradient(120deg, rgba(98, 214, 239, 0.04), transparent 44%),
    linear-gradient(240deg, rgba(241, 120, 143, 0.04), transparent 48%);
}

.breakpoints::before {
  content: "";
  position: absolute;
  inset: 0;
  pointer-events: none;
  background-image:
    linear-gradient(rgba(243, 239, 231, 0.035) 1px, transparent 1px),
    linear-gradient(90deg, rgba(243, 239, 231, 0.035) 1px, transparent 1px);
  background-size: 72px 72px;
  mask-image: linear-gradient(90deg, transparent, black 18%, black 82%, transparent);
  -webkit-mask-image: linear-gradient(90deg, transparent, black 18%, black 82%, transparent);
}

.breakpoint-grid {
  position: relative;
  display: grid;
  grid-template-columns: repeat(4, minmax(0, 1fr));
  gap: 14px;
  margin-top: 42px;
}

.break-card {
  position: relative;
  min-height: 292px;
  display: flex;
  flex-direction: column;
  padding: 22px;
  border: 1px solid var(--line);
  border-radius: var(--radius);
  overflow: hidden;
  background:
    radial-gradient(circle at 50% 18%, rgba(98, 214, 239, 0.12), transparent 38%),
    rgba(15, 17, 21, 0.72);
  transition: transform 180ms ease, border-color 180ms ease, background 180ms ease;
}

.break-card::before {
  content: "";
  position: absolute;
  left: 0;
  top: 0;
  width: 100%;
  height: 3px;
  background: linear-gradient(90deg, var(--cyan), var(--green), var(--amber));
  opacity: 0.62;
}

.break-card:hover {
  transform: translateY(-3px);
  border-color: rgba(98, 214, 239, 0.48);
}

.break-card.active {
  border-color: rgba(129, 211, 154, 0.42);
}

.break-status {
  display: inline-flex;
  width: fit-content;
  min-height: 28px;
  align-items: center;
  padding: 0 10px;
  border: 1px solid rgba(129, 211, 154, 0.28);
  border-radius: 999px;
  color: var(--green);
  background: rgba(129, 211, 154, 0.08);
  font-family: var(--mono);
  font-size: 11px;
  letter-spacing: 0.05em;
  text-transform: uppercase;
}

.break-card h3 {
  margin: 22px 0 0;
  font-size: 16px;
  line-height: 1.25;
}

.break-card p {
  margin: 14px 0 26px;
  color: var(--muted);
  font-size: 14px;
  line-height: 1.55;
}

.break-meta {
  display: block;
  margin-top: auto;
  padding-top: 20px;
  color: var(--dim);
  font-family: var(--mono);
  font-size: 10px;
  letter-spacing: 0.06em;
  text-transform: uppercase;
}

.featured-guide {
  display: grid;
  grid-template-columns: minmax(0, 0.95fr) minmax(320px, 0.6fr);
  gap: 26px;
  margin-top: 40px;
  align-items: stretch;
}

.guide-card {
  padding: clamp(24px, 4vw, 38px);
}

.guide-card .meta {
  display: flex;
  flex-wrap: wrap;
  gap: 10px;
  margin-bottom: 18px;
}

.chip {
  display: inline-flex;
  align-items: center;
  min-height: 28px;
  padding: 0 10px;
  border: 1px solid var(--line);
  border-radius: 999px;
  color: var(--muted);
  font-family: var(--mono);
  font-size: 11px;
  letter-spacing: 0.05em;
  text-transform: uppercase;
}

.guide-card h3 {
  max-width: 680px;
  font-family: var(--serif);
  font-size: clamp(24px, 3.5vw, 40px);
  line-height: 1.08;
  letter-spacing: -0.018em;
}

.guide-card .button {
  margin-top: 26px;
}

.proof-stack {
  display: grid;
  gap: 12px;
}

.proof-item {
  padding: 18px;
  border: 1px solid var(--line);
  border-radius: var(--radius);
  background: rgba(243, 239, 231, 0.035);
}

.proof-item strong {
  display: block;
  color: var(--green);
  font-family: var(--mono);
  font-size: 12px;
  letter-spacing: 0.08em;
  text-transform: uppercase;
}

.proof-item span {
  display: block;
  margin-top: 6px;
  color: var(--muted);
}

.site-footer {
  display: flex;
  justify-content: space-between;
  gap: 24px;
  flex-wrap: wrap;
  padding: 30px clamp(20px, 5vw, 64px);
  border-top: 1px solid var(--line);
  color: var(--dim);
  font-family: var(--mono);
  font-size: 11px;
  letter-spacing: 0.06em;
  text-transform: uppercase;
}

.article-hero {
  padding: 76px clamp(20px, 5vw, 64px) 52px;
  border-bottom: 1px solid var(--line);
}

.article-hero-inner {
  width: min(100%, 1060px);
  margin: 0 auto;
}

.article-hero h1 {
  max-width: 880px;
  margin: 0;
  font-family: var(--serif);
  font-size: clamp(38px, 5.6vw, 72px);
  line-height: 1.02;
  letter-spacing: -0.025em;
  font-weight: 500;
}

.article-deck {
  max-width: 820px;
  margin: 24px 0 0;
  color: var(--muted);
  font-size: clamp(18px, 2vw, 22px);
}

.article-meta {
  display: flex;
  flex-wrap: wrap;
  gap: 10px;
  margin-top: 28px;
}

.article-visual {
  margin: clamp(28px, 4vw, 46px) 0 0;
  padding: 8px;
  border: 1px solid rgba(210, 162, 90, 0.24);
  border-radius: var(--radius);
  background:
    linear-gradient(135deg, rgba(210, 162, 90, 0.12), rgba(98, 214, 239, 0.04)),
    rgba(5, 5, 5, 0.72);
  box-shadow: 0 24px 70px rgba(0, 0, 0, 0.32);
}

.article-visual img {
  display: block;
  width: 100%;
  height: auto;
  border-radius: calc(var(--radius) - 4px);
}

.article-layout {
  display: grid;
  grid-template-columns: minmax(0, 260px) minmax(0, 820px);
  gap: 54px;
  width: min(100%, 1120px);
  margin: 0 auto;
  padding: 54px clamp(20px, 5vw, 64px) 90px;
}

.toc {
  position: sticky;
  top: 98px;
  align-self: start;
  padding: 18px;
  border: 1px solid var(--line);
  border-radius: var(--radius);
  color: var(--muted);
  background: rgba(15, 17, 21, 0.74);
}

.toc strong {
  display: block;
  margin-bottom: 12px;
  color: var(--text);
  font-family: var(--mono);
  font-size: 11px;
  letter-spacing: 0.1em;
  text-transform: uppercase;
}

.toc a {
  display: block;
  padding: 7px 0;
  color: var(--muted);
  text-decoration: none;
  font-size: 14px;
}

.toc a:hover {
  color: var(--cyan);
}

.article {
  min-width: 0;
}

.article section {
  scroll-margin-top: 100px;
  padding: 0 0 46px;
  margin: 0 0 46px;
  border-bottom: 1px solid var(--line);
}

.article section:last-child {
  border-bottom: 0;
  margin-bottom: 0;
  padding-bottom: 0;
}

.article h2 {
  margin: 0 0 18px;
  font-family: var(--serif);
  font-size: clamp(27px, 3.5vw, 42px);
  line-height: 1.08;
  letter-spacing: -0.014em;
  font-weight: 500;
}

.article h3 {
  margin: 28px 0 10px;
  font-size: 18px;
}

.article p {
  color: var(--muted);
  margin: 0 0 18px;
}

.article ul,
.article ol {
  color: var(--muted);
  margin: 0 0 20px;
  padding-left: 22px;
}

.article li {
  margin: 7px 0;
}

.article strong {
  color: var(--text);
}

.callout {
  margin: 24px 0;
  padding: 18px 20px;
  border: 1px solid var(--line);
  border-left: 3px solid var(--cyan);
  border-radius: var(--radius);
  background: rgba(98, 214, 239, 0.06);
}

.callout.warning {
  border-left-color: var(--amber);
  background: rgba(246, 160, 77, 0.07);
}

.callout.success {
  border-left-color: var(--green);
  background: rgba(129, 211, 154, 0.06);
}

.callout p:last-child {
  margin-bottom: 0;
}

.quick-path {
  display: grid;
  grid-template-columns: repeat(2, minmax(0, 1fr));
  gap: 10px;
  margin: 24px 0 4px;
}

.quick-step {
  display: grid;
  grid-template-columns: 42px 1fr;
  gap: 12px;
  align-items: start;
  padding: 14px;
  border: 1px solid var(--line);
  border-radius: var(--radius);
  background: rgba(243, 239, 231, 0.035);
}

.quick-step span {
  color: var(--cyan);
  font-family: var(--mono);
  font-size: 11px;
  letter-spacing: 0.08em;
}

.quick-step strong {
  color: var(--text);
  font-size: 14px;
  line-height: 1.42;
  font-weight: 600;
}

.code-block {
  position: relative;
  margin: 18px 0 26px;
  border: 1px solid var(--line);
  border-radius: var(--radius);
  overflow: hidden;
  background: #0d0f12;
}

.code-title {
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 12px;
  padding: 10px 12px;
  border-bottom: 1px solid var(--line);
  color: var(--dim);
  font-family: var(--mono);
  font-size: 11px;
  letter-spacing: 0.08em;
  text-transform: uppercase;
}

.copy-button {
  border: 1px solid var(--line);
  border-radius: 5px;
  color: var(--muted);
  background: rgba(243, 239, 231, 0.04);
  font-family: var(--mono);
  font-size: 10px;
  letter-spacing: 0.08em;
  text-transform: uppercase;
  padding: 6px 8px;
  cursor: pointer;
}

.copy-button:hover {
  color: var(--text);
  border-color: var(--cyan);
}

pre {
  margin: 0;
  padding: 16px;
  overflow-x: auto;
}

code {
  font-family: var(--mono);
  font-size: 13px;
}

pre code {
  color: #e8e2d9;
}

.check-grid {
  display: grid;
  grid-template-columns: repeat(2, minmax(0, 1fr));
  gap: 12px;
  margin: 22px 0;
}

.check-item {
  border: 1px solid var(--line);
  border-radius: var(--radius);
  padding: 16px;
  background: rgba(243, 239, 231, 0.035);
}

.check-item strong {
  display: block;
  margin-bottom: 6px;
}

.back-link {
  display: inline-flex;
  margin-top: 28px;
  color: var(--cyan);
  font-family: var(--mono);
  font-size: 12px;
  letter-spacing: 0.06em;
  text-transform: uppercase;
  text-decoration: none;
}

.back-link:hover {
  color: var(--text);
}

@media (max-width: 920px) {
  .featured-guide,
  .article-layout {
    grid-template-columns: 1fr;
  }

  .lane-grid,
  .breakpoint-grid,
  .check-grid,
  .quick-path {
    grid-template-columns: 1fr;
  }

  .toc {
    position: static;
  }
}

@media (max-width: 820px) {
  .opstack-card {
    grid-template-columns: 1fr;
    gap: 22px;
  }

  .opstack-bullets {
    padding-left: 0;
    border-left: 0;
    border-top: 1px solid rgba(243, 239, 231, 0.075);
    padding-top: 18px;
  }

  .opstack-gate {
    flex-direction: column;
    align-items: flex-start;
  }

  .opstack-gate-copy {
    text-align: left;
  }

  .opstack-head {
    flex-direction: column;
    align-items: flex-start;
    gap: 6px;
  }
}

@media (max-width: 860px) {
  .site-header {
    align-items: flex-start;
    flex-direction: column;
  }

  .site-nav {
    width: 100%;
    overflow-x: auto;
    padding-bottom: 2px;
  }
}

@media (max-width: 680px) {
  .hero {
    padding-top: 46px;
  }
}

@media (prefers-reduced-motion: reduce) {
  *,
  *::before,
  *::after {
    animation-duration: 0.01ms !important;
    animation-iteration-count: 1 !important;
    scroll-behavior: auto !important;
    transition-duration: 0.01ms !important;
  }
}